The present invention relates to a damper for a diaphragm spring in a friction clutch used in automobiles and others.
Generally, as disclosed in U.S. patent application Ser. No. 703,473, now U.S. Pat. No. 4,633,990, a diaphragm spring of a clutch cover assembly is arranged in and supported by a clutch cover for forcing the pressure plate toward a friction facing of a clutch disc. The clutch cover is fixed to a flywheel of an engine. The diaphragm spring has radial fingers which extend from the inner priphery of the spring to a radially middle portion thereof. The outer ends of the fingers integrally continue to an radially outer annular portion of the spring, and the inner ends of the fingers are free ends.
In the above structure, when an axial vibration of the engine, to which the clutch is assembled, is transmitted through the clutch cover to the diaphragm spring, the fingers having the free ends may resonate.
This resonance causes a vibration of the pressure plate, which prevents smooth and uniform engaging operation of the clutch, and also, causes judder and noise.
Accordingly, it is an object of the invention to provide an improved structure, overcoming the above-noted problems.